A display apparatus as a device having a display panel to display images based on various formats of image signals/image data is implemented as a television (TV), a monitor and so on. The display panel is implemented in various configuration types, such as a liquid crystal panel, a plasma panel, etc., according to its properties and is applying to all sorts of display apparatuses.
Due to electrical, physical and optical characteristics, the display apparatus generates changes or modifications in luminance and chromaticity, which are light outputs of pixels, on the reproduced images. Accordingly, when an image signal provided from the same input source is displayed on different display apparatuses, the image signal is reproduced somewhat differently in color. For example, even if the same broadcasting program is provided to the display apparatus via terrestrial or satellite broadcasting, colors shown by the same broadcasting program on the display apparatus are slightly different according to reproducing display apparatuses.
Also, in a high definition display apparatus, if the light outputs of pixels are not uniform, a problem, such as screen blurring or the like, may occur.
To address such a problem, calibration, which makes a light output of the display panel uniform, is used. FIG. 1 illustrates a display apparatus 1 according to a related art and a spectrophotometer 2 for measuring an image outputted from the display apparatus 1 to calibrate a light output of the display apparatus 1. Uniformity calibration between the pixels is performed by measuring and analyzing displayed images using the spectrophotometer to identify calibration coefficients, providing the identified calibration coefficients to the display apparatus 1, and applying the calibration coefficients to the displayed images to make light outputs of the pixels uniform. What the light outputs of the pixels are uniform is means that light outputted from the pixels of the display apparatus 1 based on the received image signals in the same gradation is uniform in luminance and chromaticity.
The Uniformity calibration of the display apparatus 1 according to a related art has been performed by measuring an image in a specific gradation using the spectrophotometer 2 to calculate a calibration coefficient for improving uniformity for the image, and applying the calculated calibration coefficient to all different gradations of the image signal.